The present invention relates to sulfur-containing coals and more particularly to a method of reducing sulfurous pollutants from furnaces fired with sulfur-containing coals.
The present energy shortage has accelerated the search for fuel sources to supplement diminishing gas and oil supplies. Because of its abundance, vegetation is one potential energy source being seriously investigated. While tress have been an important fuel source, current efforts are directed toward more easily replenished vegetation such as green crops in feedstock such as grass, leaves and unused portions of green plants (e.g. stems). Feedstock materials could be theoretically burned, fermented or reacted chemically with other materials to release energy. The energy which could be derived from farmlands can equal that derived from all the natural gas produced in the United States. However, green crops normally would not be considered to constitute an economically desirable energy source until an economical method is devised for extracting values such as protein and glucose therefrom and the conversion of glucose to fuel values such as alcohol. Further, the cost of fossil fuel is not at a level which would make use of green crops for fuel economical. In addition, there is the need to balance the loss of foodstuffs against the necessity to generate energy to supplement diminishing fossil fuel sources. Thus, it can be seen that for purposes of economics, when using green crops it is important to consider both food and fuel values.
Perennial plants such as grass and legumes can provide a particularly economical fuel supply if the food values, such as protein and glucose, contained therein can be extracted efficiently. Additionally, perennials can flourish on land unsuitable for most crops, have a short growing season and substantially eliminate loss of topsoil due to erosion.
In view of these problems, it would be advantageous to have a method for economically extracting the food values from green crops. Further, it can be seen that it would be advantageous to provide a method of extracting food values from green crops or plants which permits recovery of the residue as a fuel source.